The present invention relates to a device for braking the movement of a movable member with respect to a support structure.
A device of this type is known for example from German Utility Model DE 296 04 260 U1, which describes a tilting handle provided with a handgrip articulated on a mounting wall of a vehicle. The handgrip is rotatable against the action of resilient means from a rest position, close to the mounting wall, to an operating position. The handgrip is brought automatically from the operating position to the rest position after being released by the user. The return movement to the rest position is made softer by a braking device which acts on the axis of rotation of the handgrip.
The braking device is produced as a rotary damper, comprising a cylindrical casing, which defines within it an annular chamber filled with a viscous medium, a rotor mounted in a sealed manner on the casing and rotatable in the annular chamber, and a central through-opening, which is provided in the casing, and within which the axis of rotation of the handgrip is arranged.
The conventional rotary dampers normally used in the above-mentioned application do not, in reality, make it possible to obtain very high braking torques (customarily not more than a few N·cm), which limits their range of use. Moreover, the braking action on the rotor is developed not only by the viscous fluid contained in the device, but also to a large extent by the sealing O-rings interposed between the rotor and the casing, which makes the performance of the device substantially dependent on the operating temperature and percentage of humidity.
It is an aim of the present invention to provide a braking device of compact dimensions which makes it possible to obtain substantially higher braking torques than the prior art, without exhibiting the problems of reliability described above.